adding No3 to lower Po4

[chris&barb]

there is a discussion going on in our local club forum about this and i was wondering what everyone here thought about it. it seem very interesting to me because i have a fuge with macro and if it would work all i would have to do is change the macro that im growing. well anyway here it is.what do you think?

http://www.reefcentral.com/forums/showthread.php?s=&threadid=717867

 

[MikeS]

Hmmm....adding nitrate to the system so your macroalgae will be more efective phopshate removers....kinda spooky to me...:lol:

 

[Curtswearing]

I really didn't read the thread...I just glanced. There's some evidence to suggest that macroalgaes can be Iron limited as well.

I've never understood the concept of adding Nitrates to make macro's grow better. It seems to me that the better idea is to minimize P inputs rather than add additional nutrients to help macroalgaes absorb more P.

The only way this would work though is if you are Nitrogen limited which most people are not.

 

[MikeS]

I've never understood the concept of adding Nitrates to make macro's grow better. It seems to me that the better idea is to minimize P inputs rather than add additional nutrients to help macroalgaes absorb more P.

My thinking exactly Curt....I've seen this approach in FW planted aquariums, but the philosophy is 100% different than that of reefkeeping....they strive for a nutrient rich system to encourage the growth of the plants, but they do not have the delicate invertibrates in their system that don't tolerate these conditions like we do....I don't like the concept of introducing one nutrient into the reef system simply to facilitate the removal of another....

MikeS

 

[chris&barb]

I agree its something that go's against the norm. But the way im reading it is that you would only have to add very small amounts of No3 at a time to keep the Macro or Seagrass growing rapidly and then it would be able to continue to take up Po4.
Ive noticed in my fuge with calurpa that in a short time the growth slow's or stops when it get on the full side, then after i prune it a few days later it takes off again.Now i know you could say Prune it more ofter but if this could work couldnt you keep a small amount of what ever in your fuge and keep it growing at a faster rate and keep the P in check with out using GFO?

 

[MadTownMax]

It seems to me that the better idea is to minimize P inputs rather than add additional nutrients to help macroalgaes absorb more P.

If you have a fish-less system, this may be possible, but basically, from the test results from most peoples tanks, with fish, the input of food (leftovers) and the fish waste (even after break-down from bacteria) has a lower ratio of nitrogen to Phosphate (too much phosphate) for macro algaes to have the capacity to remove it.

I'm definately not saying this is the be-all end-all of aquarium maintenence, but thought it might help people better understand exactly how to run a refugium for nutrient export by using macroalgaes that match their tanks Nitrogenhosphate ratio rather than picking a species of macroalgae at random, or one that works for another person's tank.

this N ratio difference between tanks would definately help explain why some people have such success w/ refugiums (or certain macros), while others have such a difficult time with cuttings of the exact same specimen.

It may be a question of either running GFO or dosing small amounts of nitrate - in the latter case to export phosphate via natural means (which many people prefer to chemical scrubbers) - it would also be helpful to know which method - macroalgaes or GFO - can maintain the lowest amount of phosphate in a system with the least amount of hassle.

Personally I'm kinda hoping that I can dose both kalk and a dilute nitrate solution using my dual-channel peristaltic pump and that would significantly make this an easy process (if the nitrate-dosing solution works that is)

 

[MikeS]

I agree its something that go's against the norm. But the way im reading it is that you would only have to add very small amounts of No3 at a time to keep the Macro or Seagrass growing rapidly and then it would be able to continue to take up Po4.

I see what they are trying to do here...but why even walk that tightrope in the first place when phosphate can be dealt with by other means like phosphate removing media? I'm not a big fan of introducing one problem nutrient to deal with another...seems to me you have to maintain a fine balance in order to make it work...and if you misjudge that balance, all of a sudden you may have a bigger problem on your hands than you did to start with...

Ive noticed in my fuge with calurpa that in a short time the growth slow's or stops when it get on the full side, then after i prune it a few days later it takes off again.Now i know you could say Prune it more ofter but if this could work couldnt you keep a small amount of what ever in your fuge and keep it growing at a faster rate and keep the P in check with out using GFO?

And herein lies the problem with relying heavily on any biological processes to remove nutrients...you are dealing with a constant state of flux...one thing always trying to keep up with something else and back and forth...don't get me wrong, they have their place in the reef tank, but they are unstable, and thus hard to control...I'd put this practice of NO3 introduction in the same category as vodka dosing, zeovit, probiotics, ect....

MikeS

 

[MadTownMax]

I see what they are trying to do here...but why even walk that tightrope in the first place when phosphate can be dealt with by other means like phosphate removing media?

Just offering a different method that (if it works) may involve less maintenence, and much, much cheaper than GFO.

And herein lies the problem with relying heavily on any biological processes to remove nutrients...you are dealing with a constant state of flux...one thing always trying to keep up with something else and back and forth...don't get me wrong, they have their place in the reef tank, but they are unstable, and thus hard to control...I'd put this practice of NO3 introduction in the same category as vodka dosing, zeovit, probiotics, ect....

MikeS

Well, being that no one is trying this yet, it's hard to say how difficult it is to do, kind of putting the cart in front of the horse by dismissing an idea before it has been proven right or wrong

being that this would be very dilute dosing of nitrate (keeping levels at 1-2ppm) if dosing was applied to a separate refugium with very low exchange w/ the main system (like 1X hour) it would be plausable that the macro would uptake the nitrate before it could make it to the tank.

I'm going to talk w/ my club's Macro-expert about some nitrate sources she suggested and try this in a fuge on a new tank and let you guys know how it goes.

 

[MadTownMax]

just had another idea - wet/dry filters are supposed to be nitrate factories, maybe incorporating one of these would supply the necessary boost in nitrate, with an adjoining refugium.... just an idea

 

[Curtswearing]

Well, being that no one is trying this yet, it's hard to say how difficult it is to do, kind of putting the cart in front of the horse by dismissing an idea before it has been proven right or wrong

This isn't anything new....this is merely manipulation of the Redfield ratio to scew towards a particular macroalgae. I did this years ago when I was determined to do things the "natural" way. I dosed Iron as well as Potassium nitrate.

The problem was that I couldn't get only the macroalgae to take the nutrients and I had small microalgae blooms on occasion. I decided that the smarter approach was to buy a more suitable protein skimmer and rely less of my fuge. I went from a prizm on a 75g to a remora pro and that's when my tank truly looked it's best.